U.S. patent application number 10/691786 was filed with the patent office on 2004-05-06 for bearing apparatus.
This patent application is currently assigned to Koyo Seiko Co., Ltd.. Invention is credited to Kashiwagi, Shinichirou, Kawatani, Teruyuki, Takahashi, Kenji, Toda, Kazutoshi, Wakisaka, Teruyuki.
Application Number | 20040083612 10/691786 |
Document ID | / |
Family ID | 18711046 |
Filed Date | 2004-05-06 |
United States Patent
Application |
20040083612 |
Kind Code |
A1 |
Toda, Kazutoshi ; et
al. |
May 6, 2004 |
Bearing apparatus
Abstract
A bearing is mounted on a hollow shaft of a hub wheel. A shaft
end of the hollow shaft is deformed radially outward and caulked to
an outer end face of an inner ring of the bearing. Between a first
area in which a spline portion is formed and a second area in which
a caulked portion is formed, between a bending starting point for
bending the shaft end radially outward and an end face of the shaft
end on an inner peripheral face of the hollow shaft, a third area
for suppressing deformation of the inner peripheral face of the
hollow shaft caused by the caulking is formed. The third area
cushions deformation in the first area.
Inventors: |
Toda, Kazutoshi;
(Tondabaya-shi, JP) ; Wakisaka, Teruyuki;
(Kitakatsuragi-gun, JP) ; Takahashi, Kenji;
(Yamatokooriyama-shi, JP) ; Kawatani, Teruyuki;
(Kitakatsuragi-gun, JP) ; Kashiwagi, Shinichirou;
(Yao-shi, JP) |
Correspondence
Address: |
JORDAN AND HAMBURG LLP
122 EAST 42ND STREET
SUITE 4000
NEW YORK
NY
10168
US
|
Assignee: |
Koyo Seiko Co., Ltd.
5-8, Minamisemba 3-chome, chuo-ku
Osaka-shi
JP
542-8502
|
Family ID: |
18711046 |
Appl. No.: |
10/691786 |
Filed: |
October 23, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10691786 |
Oct 23, 2003 |
|
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09902230 |
Jul 10, 2001 |
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Current U.S.
Class: |
29/898.06 |
Current CPC
Class: |
F16C 43/04 20130101;
F16C 2326/02 20130101; F16D 1/108 20130101; Y10T 29/49536 20150115;
F16D 2001/103 20130101; B60B 27/0084 20130101; F16C 35/0635
20130101; Y10T 29/49535 20150115; F16C 19/186 20130101; B60B 27/00
20130101; B60B 27/0026 20130101; B60B 27/0094 20130101; B60B
27/0005 20130101; Y10T 29/49682 20150115; Y10T 29/49679 20150115;
Y10T 29/49696 20150115 |
Class at
Publication: |
029/898.06 |
International
Class: |
B21K 001/76 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 17, 2000 |
JP |
P2000-215658 |
Claims
What is claimed is:
1. A method for forming a bearing apparatus comprising: providing a
roller bearing having an inner ring with an inner circumferential
surface, an inner ring radial end surface, and a chamfered corner
having a chamfer radius X2 and extending from an inner
circumferential surface end point to said inner ring radial end
surface; providing a hollow shaft body having: a shaft end; an
internal splined portion having a spline pitch diameter y1 and
extending to toward said shaft end to a spline portion end point;
and a spline free portion having a thickness y2 extending from said
spline portion end point to said shaft end; calculating a distance
X1>X2(y1/y2); positioning said inner ring on said hollow shaft
such that said inner circumferential surface end point is distanced
from said spline portion end point toward said shaft end by the
distance X1; and swaging said hollow shaft outward from a bending
starting point aligned with said inner circumferential surface end
point to said shaft end to fix said inner ring.
2. The method according to claim 1, wherein said roller bearing is
a double row angular contact ball bearing with vertices of contact
angles outside of the roller bearing.
Description
[0001] This is a Divisional of application Ser. No. 09/902,230
filed Jul. 10, 2001, now Pending.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a bearing apparatus such as
a vehicle hub unit in which a rolling bearing is mounted to a shaft
body.
[0003] A rolling bearing is mounted to an outer periphery of a
shaft body of a hub wheel of a vehicle. A shaft end of the shaft
body is bulged and deformed radially outward by rolling caulking,
i.e., swaging, to be a caulked portion. This caulked portion is
caulked to an outer end face of an inner ring of the bearing to
thereby apply a pre-load to the bearing and to fix the bearing to
the shaft body.
[0004] The shaft body of the hub wheel has a hollow structure such
that a drive shaft can be inserted into the shaft body. For spline
fitting with the drive shaft, an inner periphery of the shaft body
has spline portions.
[0005] The spline portions are formed to be substantially adjacent
to the caulked portion of the shaft end and to be formed long in an
axial direction so as to mechanically connect the inner periphery
of the shaft body and the drive shaft with necessary strength.
[0006] During installation of the bearing, the spline portions are
liable to be deformed radially inward to such a degree as to
obstruct insertion of the drive shaft into the shaft body by force
applied radially outward to the shaft end during swaging the
caulked portion.
SUMMARY OF THE INVENTION
[0007] It is a main object of the present invention to provide a
bearing apparatus in which a spline portion of an inner periphery
of a shaft body is less liable to be deformed by caulking and high
accuracy of the spline portion in the shaft body can be
maintained.
[0008] Other objects, features, and advantages of the invention
will become clear by the following description.
[0009] To put it briefly, the bearing apparatus of the invention
includes a hollow shaft body and a rolling bearing mounted to an
outer peripheral face of the shaft body. A shaft end of the shaft
body is deformed radially outward and caulked to an outer end face
of an inner ring of the rolling bearing. The shaft body has on an
inner peripheral face thereof a first area in which a spline
portion in an axial direction is formed, a second area between a
bending starting point for bending the shaft end of the shaft body
radially outward and an end face of the shaft body, and a third
area between the first area and the second area for suppressing
deformation of the inner peripheral face of the shaft body by the
caulking.
[0010] According to the invention, even if the spline portion is
formed to be axially long on the inner periphery of the hollow
shaft body so as to be mechanically connected to a spline portion
on an outer periphery of a drive shaft, because the third area is
provided between the first area and the second area, the first area
does not directly receive an influence of radially outward
deformation of the shaft end caused by caulking. As a result, it is
possible to maintain high accuracy of the spline portion and the
first area is not deformed to such a degree as to obstruct
insertion of the drive shaft.
[0011] In the invention, the third area is preferably set according
to the following expression (1):
(X1/X2)>(y1/y2) (1)
[0012] where
[0013] X1 is an axial distance from a position of a caulking side
end portion of the first area to the bending starting point for
bending the shaft end of the shaft body radially outward, X2 is an
axial distance from the bending starting point to a caulking side
outer end face of the inner ring, y1 is a difference between an
outside diameter and a pitch diameter of the first area, and y2 is
a difference between an outside diameter and an inside diameter of
the shaft end of the shaft body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other objects as well as advantages of the
invention will become clear by the following description of
preferred embodiments of the invention with reference to the
accompanying drawings, wherein:
[0015] FIG. 1 is a vertical sectional view of a hub unit according
to the preferred embodiment of the present invention in a state
before a hollow shaft of a hub wheel is caulked;
[0016] FIG. 2 is a vertical side sectional view of the hub unit
according to the preferred embodiment of the invention in a state
after the hollow shaft of the hub wheel is caulked;
[0017] FIG. 3 is an enlarged sectional view of spline-fitted
portions of an inner periphery of a shaft body of the hub wheel and
an outer periphery of a drive shaft in the hub unit;
[0018] FIG. 4 is an enlarged plan view of spline-fitted portions of
the inner periphery of the shaft body of the hub wheel and the
outer periphery of the drive shaft in the hub unit; and
[0019] FIG. 5 is an enlarged sectional view of a periphery of an
inner ring of a bearing and a shaft end of the hollow shaft in the
hub unit.
[0020] In all these figures, like components are indicated by the
same numerals.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] A preferred embodiment of the present invention is described
below with reference to FIGS. 1 to 5. A vehicle hub unit is taken
as an example of a bearing apparatus. However, balls and the like
are not shown in FIG. 5 for ease of illustration.
[0022] The hub unit 10 includes a hub wheel 11 and a bearing 12.
The bearing 12 is a double row angular contact ball bearing with
vertices of contact angles outside of the bearing and is an example
of a rolling bearing of a diagonal contact type.
[0023] The hub wheel 11 includes a flange 13 which is in a radially
outward orientation and to which a wheel (not shown) is mounted and
a hollow shaft 14.
[0024] The bearing 12 includes one inner ring 15 fitted over a
small-diameter outer peripheral face of the hollow shaft 14 and
having a single race, a single outer ring 16 having two rows of
races, a plurality of balls 17 disposed in two rows, and two snap
cages 18. As the inner ring 15, an inner ring of a general single
row angular contact ball bearing is used as it is.
[0025] In the bearing 12, a large-diameter outer peripheral face of
the hollow shaft 14 is used as another inner ring.
[0026] The flange 19 is provided to an outer periphery of the outer
ring 16 in the radially outward orientation.
[0027] A shaft end 14a of the hollow shaft 14 is caulked to a
caulking side outer end face of the inner ring 15 from the state in
FIG. 1 to the state in FIG. 2. As a result of this caulking, the
shaft end 14a becomes a caulked portion.
[0028] In a caulked state in FIG. 2, the hub unit 10 is mounted
between a drive shaft 20 and a shaft case 21 of a vehicle.
[0029] In other words, the hollow shaft 14 of the hub wheel 11 is
spline-fitted over the drive shaft 20 and connected to the drive
shaft 20 through a nut 22. The flange 19 of the outer ring 16 of
the bearing 12 is connected to the shaft case 21 through a bolt 23
so as not to rotate.
[0030] A spline portion 14b is formed on an inner periphery of the
hollow shaft 14 and another spline portion 20a is formed on an
outer periphery of the drive shaft 20. Through both the spline
portions 14b and 20a, the spline fitting is carried out.
[0031] A fitted state of the spline portions 14b of the hollow
shaft 14 and the spline portions 20a of the drive shaft 20 is as
shown in FIGS. 3 and 4. In other words, the respective spline
portions 14b and 20a are spaced uniformly in circumferential
directions and are in involute shapes. In this case, shapes of both
the spline portions 14b and 20a are not limited to the involute
shapes but may be other shapes.
[0032] The spline portions 14b of the hollow shaft 14 are inclined
in the circumferential direction. First sides of the spline
portions 14b in the circumferential direction are in contact with
first sides of the spline portions 20a of the drive shaft 14 in the
circumferential direction while the second sides of the spline
portions 14b in the circumferential direction are in contact with
the second sides of the spline portions 20a in the circumferential
direction.
[0033] Referring to FIG. 5, in the hollow shaft 14, a spline
portion forming area (first area) 141 includes the spline portions
14b and a caulked portion forming area (second area) 142 includes
the caulked portion 14a.
[0034] Between the first and second areas 141 and 142, a cushioning
area (third area) 143 for suppressing deformation of the inner
peripheral face of the hollow shaft 14 caused by caulking of the
shaft end 14a of the hollow shaft 14 is provided.
[0035] Therefore, influence of caulking of the shaft end 14a of the
hollow shaft 14 on the first area 141 is cushioned by the third
area 143. As a result, deformation of the first area 141 due to the
caulking is alleviated or suppressed.
[0036] Thus, high accuracy of the spline portions 14b in the first
area 141 can be maintained even after the caulking and such a
degree of deformation of the spline portions 14b as to obstruct
insertion of the drive shaft 20 can be prevented.
[0037] The first area 141 is an area between axially opposite end
faces of the spline portions 14b formed on the inner periphery of
the hollow shaft 14 and a caulking side end face on a pitch circle
line of the spline portion 14b is defined as a caulking side end
portion A of the first area 141.
[0038] The second area 142 is an area from a bending starting point
B of the shaft end 14a of the hollow shaft 14 to an end face of the
shaft end 14a. An inner peripheral edge portion 15a of a caulking
side outer end face of the inner ring 15 is chamfered round, e.g.,
with a quarter of a circumference of a radius of curvature X2 from
a center O. A point of intersection of a radial line from the
center O and the inner peripheral edge portion l5a is defined as
the bending starting point B.
[0039] The third area 143 is an area between the caulking side end
portion A and the bending starting point B.
[0040] If a difference between an outside diameter Do of the hollow
shaft 14 and a pitch diameter Dp of the spline portion 14b is y1, a
difference between the outside diameter Do and an inside diameter
D1 of the hollow shaft 14 is y2, an axial distance (corresponding
to an axial length of the third area 143) from the caulking side
end portion A of the spline portion 20b to the bending starting
point B is X1, and an axial distance from the bending starting
point B to the caulking side outer end face of the inner ring 15 is
X2, a position of the third area 143 is set according to the
following expression (1).
(X1/X2)>(y1/y2) (1)
[0041] Setting the position of the third area 143 by using the
above expression (1) is preferable because production of the hollow
shaft 14, i.e., settings of positions in which the spline portions
are formed and the shaft end which will be the caulked portion and
the like are easy.
[0042] A ground for the above expression (1) will be described. The
following expression (2) is obtained by transforming the expression
(1).
X1>X2(y1/y2) (2)
[0043] Here, X2 is the axial distance from the bending starting
point B to the caulking side outer end face of the inner ring 15.
This is based on setting the axial length X1 of the third area 143
at a large value because the influence of deformation in caulking
the shaft end 14a of the hollow shaft 14 on the first area 141
becomes large when the radius of curvature of chamfering of the
inner peripheral edge portion 15a of the inner ring 15 becomes
large or when a ratio between y2 and y1, i.e., a ratio between wall
thicknesses of the first and second areas 141 and 142 becomes
large.
[0044] The invention can be similarly applied to a vehicle hub unit
having a hollow shaft with a bottom in an axial direction. The
invention can be similarly applied to a vehicle hub unit for a
vehicle follower wheel.
[0045] While there has been described what is at present considered
to be preferred embodiments of this invention, it will be
understood that various modifications may be made therein, and it
is intended to cover in the appended claims all such modifications
as fall within the true spirit and scope of this invention.
* * * * *